The relation between the presence of intestinal bacteria in the perianal abscess and the anticipated perianal fistula.

Abstract

Background: Perianal abscess and fistulas are frequently encountered in our surgical practice; however, very little has been written about them. The clinical effectiveness of pus swabs for microbiological analysis during  incision and drainage of perianal abscess is controversial. Its cost implication is often overlooked.
Objectives: To assess whether the culture of pus swab following incision  and drainage of perianal abscess has any significant impact on surgical outcome and on early anticipation of development of fistula in-ano in our local population.
Patients and methods: A non-probability sample, total coverage  multicenteric cross-sectional study. All consecutive cases of incision and drainage of perianal abscess between November 2008 and June 2011 were enrolled into our study after acceptance of a pre-given informed consent.
Results: Out of 76 patients with perianal abscess included in the study only 62 patients were available for the final assessment (9 F: 53 M; age range: 18–63 years; mean ± SD: 37.66 ± 10.67). Median follow-up was 2 months irrespective to culture result. The mean hospital stay was 1.44 days, and is affected by the presence of associated illness (p=0.02). Skin flora organisms, heavy mixed growth of both skin flora and intestinal  organisms, and no bacterial growth were isolated from 75.8%, 12.9% and 11.3% respectively. Fistula in-ano developed in 16.7%, 83.3% and 0%
respectively. 83.3% of fistula developed in the group of patient who  presented ≥ 10 days, which is statistically found to be significant p=0.003. Fistula was developed in 7.1% (4/56) of patients who were treated under general anaesthesia, and in 33.3% (2/6) of patients who were treated  under local anaesthesia.
Conclusions: The preliminary findings suggest that microbiological results have correlation with presence of fistula in-ano. The result warranted us to submit pus swabs from perianal abscess for assessment as it affect clinical effectiveness of treatment, and that culture of pus in perianal abscess is an essential part of its management.

Keywords: Anal pain; Abscess; Fistula; Intestinal bacteria.